UK retailers enjoyed some respite from tough trading conditions in May as glorious weather late in the month provided a "feel-good boost" to hard-pressed consumers, a key survey reveals today.

The British Retail Consortium (BRC) has calculated that the total value of UK retail sales in May was up 3.4% on the same month last year. This followed a 1% year-on-year decline in sales value in April, a month of fairly grim weather.

However, year-on-year growth in sales volumes, as opposed to value, is likely to have been modest at best in May given that the most up-to-date figure for annual UK consumer prices index inflation, for April, is 3%.

The BRC said that skirts, shorts, and swimwear sold well in late May as the weather improved and also highlighted a strong performance by garden centres.

Stephen Robertson, director-general of the BRC, said: "As the relentlessly difficult underlying conditions continue to make trading tough for retailers, any temporary boost is of even greater importance and retailers had plenty of reason to celebrate the eventual arrival of summer at the end of May.

"Much of the month's positive performance can be attributed to spending in the final week – when consumers responded enthusiastically to the sun coming out.

"It's likely the prolonged wet period helped create pent-up demand and people also felt more relaxed about their spending as the sun created a feel-good boost.

"Small numbers of customers buying jeans and knitwear in the first weeks of May became many more people purchasing skirts, shorts and swimwear by the end of the month.

"Womenswear had its best growth this year, while garden centres enjoyed a boom in the number of people investing in new lawnmowers to tackle overgrown grass."

May sales figures for Scotland are due to be published by the Scottish Retail Consortium next week.

The SRC reported last month that Scottish retail sales value in April was down 4.1% on the same month of 2011 – the sharpest year-on-year fall since comparable records began in 1999.

This steeper year-on-year slide in sales value in Scotland than in the UK as a whole in April continued a pattern evident in the SRC and BRC figures in recent times of high street spending being weaker north than south of the Border.

Ian Shearer, director of the SRC, noted last month that "times are tough for Scottish customers and retailers".

The Scottish figures for May would seem likely to show a similar type of weather-related boost to sales as that reported by the BRC for the UK as a whole.

Helen Dickinson, head of the retail practice of accountancy firm and BRC survey sponsor KPMG, cited a likely boost to retailers from the Queen's Diamond Jubilee but emphasised conditions were tough.

She said: "Retailers are hoping that the Jubilee celebrations will have helped to pull them out of the mire, but a short-term patriotic spending spree will not overcome the underlying difficulties facing the industry –which remains under pressure from a combination of declining consumer confidence and squeezed incomes."